Determines the current dataset type based on EXPO_PUBLIC_DATASET_TYPE or NODE_ENV
Priority: EXPO_PUBLIC_DATASET_TYPE takes precedence if set, otherwise falls back to NODE_ENV
'production' if the active variable is 'production', 'performance' for performance testing, otherwise 'test'
Determines the current dataset type based on EXPO_PUBLIC_DATASET_TYPE or NODE_ENV
Priority: EXPO_PUBLIC_DATASET_TYPE takes precedence if set, otherwise falls back to NODE_ENV